Tag Archives: spectroscopy

Specola Guestbook: August 31, 1913 – Edward Pickering

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This entry is part 40 of 53 in the series Specola Guestbook

Since its founding in 1891, many people have passed through the doors of the Vatican Observatory.  A quick perusal of our guestbook reveals several Names, including Popes, nobel laureates, astronauts, actors, and saints. Today’s guestbook entry is from August 31, 1913, when Edward Pickering made a visit. Next to his name, Edward Charles Pickering FMRS HFRSE (1846-1919) wrote “Director of Harvard College Observatory, Cambridge Mass, USA.” He was director of the Harvard College Observatory from 1877 until 1919. Pickering made significant advances in stellar spectroscopy. Building on early work by Fr. Angelo Secchi, he and his team of astronomers and computers (including Annie Jump Cannon) developed the Harvard Stellar Classification scheme that is still widely used today. (This is the “O.B.A.F.G.K.M.” sequence that you may have had to memorize if you ever took an introductory astronomy course.) The team produced the Henry Draper Catalog, a stellar catalog with spectroscopic classifications for more than 200,000 stars. Pickering also discovered the first … Continue reading →

Across the Universe: Father of the Future

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This entry is part 190 of 191 in the series Across the Universe

This column first ran at the end of May, 2018, in The Tablet. Why I wound up with two columns in May that year is mysterious to me… The summer of 2018 marked the 200th birthday of Father Angelo Secchi, the Jesuit priest often called the Father of Astrophysics. In May I participated in a celebration of his work held in his home town of Reggio Emilia, northern Italy. Speakers covered topics drawn from his life and career, starting with a wonderful biographical sketch by Ileana Chinnici, a historian of astronomy at the Palermo Observatory (and an adjunct Vatican astronomer).  Like Galileo, Secchi had a knack for the popularisation of science, and for becoming embroiled in political controversy. The revolutions of 1848 forced Secchi to flee Rome for two years – he spent the enforced sabbatical at Stonyhurst College and at Georgetown University – and he was nearly forced to leave again after 1870 by the manoeuvrings of enemies in the … Continue reading →

Religious Scientists: Fr. Angelo Secchi S.J. (1818-1878), Pioneer of Astrophysics

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This entry is part 2 of 15 in the series Religious Scientists of the Catholic Church

(This is the first article in the column “Religious Scientists of the Catholic Church” which looks at the lives and contributions of prominent vowed religious scientists.) The year 2018 marked the 200th anniversary of the birth of Fr. Angelo Secchi SJ, and so there have already been several articles on Fr. Secchi in this blog.  An interested reader could review any of these articles: “Ghost of elements, spectres of the universe: Angelo Secchi SJ” by Michelle Francl, Aug 8, 2018. “Solar Prominences and a Prominent Jesuit Astronomer” by Robert Macke, Oct 23, 2018. “Happy Birthday to the Father of Astrophysics!” by Guy Consolmagno, June 28, 2018. And outside the blog, here’s another article I wrote about Secchi’s oceanographic studies: “Fr. Angelo Secchi, S.J. and the Voyage of the Immacolata Concezione” by Robert Macke, International Society of Limnology webpage For the YouTube generation, here is a video to watch: Why begin this series with a scientist for whom so much has already … Continue reading →

Please Welcome our new Blogger: Chris Olsen

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Chris Olsen has a degree in history, and is a student of 19th-century photography and science. Chris does daguerreotypes and wet plate collodion, which are the two first photographic processes that were commercially successful. Chris works as an operator at Fermi National Accelerator Lab; this offers him the very special privilege of taking his camera equipment into the accelerator complex and using this 150-year-old process to take pictures of it. Chris also does backstage concert photography and takes pictures of Civil War reenactors. Chris uses his own 19th-century equipment, and gives these photographs to the Civil War reenactors as gifts. Chris will be writing a series about 19th century solar observation, and recreating the instruments used during that period. Chris has started researching the English scientist and astronomer Norman Lockyer; during the next total solar eclipse, Chris hopes to “discover” the element helium using the spectrometer he built.  

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A Note on the Explanation of the D-lines in the Spectrum of the Night Sky

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When I ran across the paper that gave the title to this post, it seemed as if it would make a wonderful title to a poem, perhaps one by Marilyn Nelson or Billy Collins, about what is hidden in plain sight – the airglow, and some of the early women in science.  The moon and stars are not the only lights in the night sky, the very envelope of air that surrounds us glows, day or night.  One of the sources of the earth’s airglow is a 3 mile deep layer of sodium atoms about 50 miles above the earth’s surface. There are roughly 8000 sodium atoms in a milliliter of air up there. In fact, there’s not much air at all, the pressure is about a millionth of what it is as sea level.  Even so, only 4 in a billion of the atoms in that layer of the atmosphere are sodium.  When these sodium atoms get energetically excited, … Continue reading →

Across the Universe: Teaching new stars

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This entry is part 80 of 191 in the series Across the Universe

This column first ran in The Tablet in June 2012 It would be hard to credit a philosopher who had never read Plato, or an expert in literature who was unfamiliar with Sappho or Homer. Every mathematician has learned Euclid’s geometry at some time (usually very early) in their studies; every artist has, at some point, encountered Praxiteles. Yet a science course that spent a significant chunk of its curriculum on Aristotle’s physics would raise eyebrows, to say the least. Jettisoning the wisdom of antiquity is a characteristic trait that differentiates science from other fields. (And of course it’s one obvious illustration of how Scripture is never a science text.) But if everything we learn from astronomy will inevitably be superseded by later work, then why do we even bother learning the current stuff? I’ve had students ask me that; and I was wondering it myself, attending the biennial Vatican Observatory Summer School being held in 2012 at our headquarters in … Continue reading →